Maybe it's because they're lazy. Maybe it's because they can't be trusted to do it right by themselves. Whatever the reason for it, this is blood search warrants for dummies:
MoCo Search Warrant
There's no such thing as a fill-in-the-blank and check-the-boxes search warrant affidavit for any other criminal offense. Judges reviewing warrants to search a house in a felony case take more time to review the affidavit for probable cause than do judges deciding whether or not to allow the state to jab a needle in a motorist's arm.
This is your government at work - against you and your rights.