On my phone so it's hard to check, but Gmail's ctrl and shift clicks work really well and is intuitive to me. I'm shocked they wouldn't use the same mechanics everywhere.

Best example: Gmail is one of the only webapps I'll ctrl click a few items at the top of the list, ctrl click a few in the middle, and then shift click to the bottom and it works exactly how I'd expect - everything stays selected and the shift+click selects from your previous click to the next item. I think it gets wonky if you change directions but I can't imagine how I'd expect ctrl+click item 1, 2, 9, 10, then shift click on 4 would work.