If people don't feel comfortable with mags, fair enough, no reason why everyone should, especially if they're happy with their charging system or inves tin a modern BTH independent spark generator.
But there is no reason at all why a decent mag won't fire a high compression engine. Yes, on methanol at 14:1 or something there could be some HT insulation issues maybe, but for anything we need they should be fine. I haven't noticed modern fuel making a jot or tittle's worth of difference on my own bikes.
All the weaknesses mentioned exist, of course they do, but so do the strengths. Firing intervals can be got right, ATDs can work, the guts can last for years and years. Magnetism doesn't just disappear on most post-war Lucas instruments and is extremely rarely the cause of failure.
Some of the electronic options don't address all the weaknesses, can introduce new possible points of failure and also steal your storage space.
It's all a question of where you feel happiest carrying the risk (and/or whether you want 'original' I suppose). I don't care about original myself very much, looking first for 'reliable' to support quite high mileages. For me, mag + dynamo + DVR2, or alternator + decent solid state regulator/rectifier + mag = 'reliable'. For others, 'reliable' may = Alton alternator/ good E3L and electronic sparks or Lucas alternator + coil etc etc.
What the hell - as long as we're out there on the road, doesn't really matter does it?