i dont have a problem with technical shirts. i personally wear technical shirts casually sometimes. who cares = free shirts = free clothing = always GREAT!
you'll usually see the novice runners race in their raceday issued t-shirts though, but you dont have to - you can race in your Nike race day outfit singlet&shorts - so dont worry what others are doing
it'd be nice though for race directors and planners to go back to a chesp hanes 100% cotton white t-shirt with minimalist design. usually helps keep costs low and no one likes paying more than 15-20bucks for your local 5k, now bigger races i can understand why they charge more but yeah 10-15 bucks for the 5k race and a free cotton tee is a good way to go IMO