I don't think there's any excuse these days for a fogged up mask, thats just scrimping on the part of the site owner.
As for the bruising, thats simply down to really cheap paint. From a site owners point of view, it's not as simple as £1 difference between boxes, it's a pallets worth, or 2, or 4 which can soon mount up into a difference of £500 per order.
I've had a site open for just over 2 years now, NOT ONCE has anyone walked out the gates saying it was too sore for them, and we chrono our guns 260-280. If we had a mask which fogged up it was on the coldest of frosty days, on a big fat sweaty hairy person. Even then we switch the mask or the lens.
Anyone having a good day will tell 5 other people, anyone having a bad day will tell anyone and everyone they can find.
I doubt this will do damage, but i do reckon in the not too distant future, paying customers will become much more savvy about their day out. At them minute the vast majority just take it as given that paintballs don't shoot even close to straight, that masks can fog up.
It won't be too long until the average joe is asking for a refund because the service some sites provide is by sub standard by any measure.