"But they haven’t stopped Swedish entrepreneurs from building giant firms like H&M, Ikea, and Tetra Pak."
Look at when the mentioned companies were founded:
IKEA - 1943
H&M - 1947
Tetra Pak - 1951
Then look at the historical tax-to-GDP ratio chart here:
http://www.ekonomifakta.se/sv/Fakta/Skatter/Skattetryck/
The companies were founded in low-tax, pre-welfare Sweden.