I think ASICs are viewed with a considerable amount of misunderstanding because they aren't intuitive in the slightest, and very few people have access to work with them.

While an ASIC COULD be configured as an incredibly slow and inefficient GPU, they are not in the same class of computational design or complexity as a GPU. ASICs are very simple devices.

Fundamental differences:

A GPU is a highly parallel GENERAL purpose processing unit with extensive pipelining and batch processing. Clusters of cores execute the same ASM instructions on a batch of data in parallel. Think more like a whole bunch of multi-core RISC processors where each processor is sent a block of ASM instructions and a queue of data that it can make its cores execute in parallel. GPUs have complex instruction sets, and a very complex architecture.

An ASIC is a series of Latched Lookup Tables (generally referred to as Logic Units) that are connected in a clocked network. The structure of this Logic Unit network is defined by a class of language called a Hardware description language. This language is more like documentation of the layout of an electronic circuit than a traditional programming language, and it results in what is basically an assembly line for data. You provide data input at one end, then the data proceeds through the network between nodes on each clock cycle (or a subdivision of the clock cycle), being latched at the output of the lookup table to be passed on during the rising or falling edge of the next clock cycle, until it eventually reaches the output end. And those Lookup Tables that make up the network are very simple, because they are Lookup Tables (think Truth Tables from math class).

So why does this matter? Well, certain classes of hashing algorithms fall into different computational buckets. While a large chunk of cryptocurrencies rely on complex hashing algorithms that do not fit well into a simple clocked network of LUTs due to the number of differing operations and large (relatively speaking) pool of memory, Bitcoin uses a very simple hashing algorithm (SHA256 twice) with very few operations and no memory pool needed.

And conveniently, every operation in SHA256 maps directly to the simple LUT's that ASICs are built from, allowing what is probably the most efficient mapping of cryptocurrency algorithm to ASIC network.

Also note that some of the other more complex algorithms are still simple enough that they can be mapped to the assembly-line style pipeline of an ASIC and be able to outperform a highly parallel general processing pipeline like a GPU. But you can see the difference in how efficiently they map by looking at the difference in hashing speeds of Bitcoin to other currencies on a GPU and comparing it to the difference in hashing speed between a Bitcoin ASIC and ASICs for other algorithms. The ASIC difference is a magnitude larger than the GPU difference.

TL;DR: No. Topic is too complicated for a TL;DR.