Technically the Makitas are hypoid drive saws, not a worm drives aren't they? And possibly a grey imports, too, as Makita don't seem to list them in the UK. Want a left blade Makita saw then look to the 18 volt cordless tools where you'll find the DSS610, DSS611, DHS680 and the DRS780 models (the latter being the nearest you'll get in a cordless tool to a worm drive saw. Biggest plus of left blade saws is that it is far easier for a right handed person to see a cut line when using them, however they do.make is more likely that the operator will stand behind the saw (and in the "firing line" in the event of a kickback) when making a cut
A bit of a history lesson? As to why they never caught on here, it might just be because unlike the USA we have simply never had the massive quantities of timber framed housing here that they have in the mid west or west coast of the USA. The technique you see commonly used in the USA is to use a chalk line to mark the cut line, plonk the saw on the plywood and use the weight of the saw to keep the it in place whilst you push it across the sheet single-handed. This isn't an accurate cut, but it is fast. You can use them to make cross cuts in joists or framing timber with the help of a speed square, but TBH they are bloody heavy beasts with the weight offset to the front (where the gearbox is) so that after an hour or so of repetitive crosscutting of joists you get heartily sick of the bloody things. Even in the USA the worm drive saw was/is common on the west coast (where houses are timber framed and use a lot of plywood and OSB) whilst on the east coast (where there are a lot more brick or block houses) the "sidewinder" dominates.
BTW, it isn't for the lack of trying to introduce them here, either, with Stanley, Black & Decker, Skill, Porter-Cable and Ingersoll (nee Millers Falls) having either offered models of worm drive saw in the UK at various times from the 1940s to the early 1970s (some British made B&Ds were actually given the name "Ripsnorter"). The problem is that these saws are very heavy when set against a conventional ("sidewinder") saw and are considerably more expensive than equivalent size conventional saws, too (so one msjor reason you'd never see a DIY brand version, methinks). On top of that, though, worm drive saws are generally limited to 184 or 190mm (7-1/4in) blades which give maybe a 65mm depth of cut. That isn't much use when you want to saw 3in timber joists for which a 9in/235 mm saw (with 80 to 85mm depth of cut) is more desirable, especially if similarly priced and a tad lighter (as they were)
I'm guessing that you've never really used one of these saws. They might well have their place, but in trade terms they've been overtaken by left blade cordless saws in Europe which are better balanced for one handed use, lighter and can be used with speed squares arguably somewhat readily (at least with less fatigue). Were I to be putting ply cladding onto roofing all the time or putting down plywood sub flooring 3 days a week I could see the point, but otherwise they aren't really that wonderful
And if you are getting a face full.of dust by leaning over the saw maybe you need to look at a rail-guided plunge saw linked up to a vacuum cleaner (or even justice dust bag and a straight guide,)... BTW I actually have the Makita DRS780 and it's a powerful beast, but other than for roofing work my plunge saw/rail combination knocks it into a cocked hat for accurate sheet material cuts and BTW almost any left blade cordless saw would be lighter and better balanced for one handed work, with or without a speed square
The 780 is also just like its' corded brethren because it throws all the waste out of to the left of the blade, all over the cut line and into my face.....
