Apple built hardware which was not particularly secure. The software defaults to a four-digit PIN. They attempt to mitigate this by adding an escalating interval between entries, and by optionally wiping the phone after too many failed tries, but this is not set in stone and those limits can be removed with a software update.
The government is coming to Apple and saying, "You can remove these limits. Do that for us on this phone." Coming as a legitimate court order, I see no problem with this request. The government isn't even asking them to crack the phone, they just want Apple to remove the limits so the government can try to brute force it. They're even paying Apple for their trouble.
If Apple didn't want to be put in a position where the government can ask them to compromise their users' privacy, they should have built hardware which even they couldn't crack. And of course they did; starting with the A7 CPUs, the "secure enclave" system prevents even Apple from bypassing these limits. The phone in question just happens to predate that change.
If the government was demanding that Apple do the impossible, I'd be on their side. If the government was demanding that Apple stop manufacturing secure phones, I'd be on their side. But here, all they're asking is for a bit of help to crack an insecure system. They're doing this in the open, with a court order. What's the problem?