Why do texans seem to celebrate drinking (and driving)?

Not sure they do: Tx has consistently ranked poorly in dui statistics. Laws may play a role, e.g. Tx is one of only 12 states that doesn't allow sobriety checkpoints. Also, according to census data, tx ranks #2 of the 50 states with the youngest residents, & the majority of dui offenders are < 30, so perhaps demographics are to blame. There is no data to support your contention that texans 'celebrate' any of this.